<style>
    .custom-error-notice {
        position: fixed;
        width: 100%;
        height: 100%;
        background-color: #1b263b; 
        color: #778da9;
        text-align: center;
        font-size: 30px;
        font-weight: bold;
        display: flex;
        justify-content: center;
        align-items: center;
    }

    body {
        overflow: hidden; 
    }
</style>
<div class="custom-error-notice">
    Error 401 - Unauthorized
</div>